Topband: Vertical SWR Problems
George & Marijke Guerin
gmguerin at voyager.net
Thu Dec 2 11:17:26 EST 2004
Hi All,
Let me address two issues.
Ground effectiveness:
To my ears the team vertical guys were not loud from 3D2XA. I believe Ken's
note about only 2 radials is the issue. One needs to have a minimum of 30
radials each about 20 meters/66 feet or longer as a minimum unless one is on
a saltwater flat.
Some years ago a crew with a Battle Creek Special in central Oceana area
only put out a few radials the first week and had a very poor signal. When
they put out the rest of the radials they put out a decent signal and worked
the entire North American continent and some Europe on their sunrise.
For what it is worth, 32 radials 1/8 wavelength long is better than 16
radials 1/4 wavelength long, as the larger number of radials handles the
near in return currents much better
Base loaded verticals:
As to base loading Titanex verticals, yes the antenna may have a 11 or 12
ohm feed point impedance, with a lot of capacitive reactance, but they
supply and/or recommend a large inductor to base load the vertical up to 160
meters. Tapping the loading coil up some number of turns from the
bottom/ground end will find a match close to 50 ohms for the coax cable feed
line.
73 George K8GG
More information about the Topband
mailing list